An EV tariff is a domestic electricity contract with a discounted overnight unit rate aimed at home charging. The cheapest options now sit between roughly 6p and 9p per kWh in the off-peak window, against a peak rate that can exceed 30p; the Ofgem default tariff cap for Q2 2026 sets the wider context for what those peak rates can legally reach.
The window length, smart meter type, and EV ownership proof requirements all vary by supplier.
Last reviewed: May 2026
TL;DR
- Off-peak windows range from 4 hours (Intelligent Octopus Go base slot) to overnight 7-hour blocks (EDF GoElectric Overnight).
- Octopus Intelligent Go gives 6 hours 23:30 to 05:30 plus extra slots scheduled by the supplier against the car's API.
- OVO Charge Anytime and Octopus Intelligent Go work without a dual-rate meter setup because the charging session is metered through the chargepoint API.
- SMETS2 smart meter is required for most multi-rate EV tariffs; SMETS1 in DCC migration is acceptable on some.
- EV ownership proof (V5C or chargepoint serial) is required for Octopus Intelligent Go, OVO Charge Anytime, E.ON Next Drive and EDF GoElectric. Octopus Go and Agile have no ownership gate.
The two structural models for an EV tariff
Every UK EV tariff fits one of two structures. The first is a time-of-use tariff: the meter logs consumption by half-hour, a discounted rate applies inside a fixed nightly window, and all consumption outside the window prices at the peak rate.
Octopus Go, EDF GoElectric, British Gas Electric Driver and Scottish Power EV Saver use this model.
The second is a charge-session model: the supplier reads consumption directly from the chargepoint or the car (via API), bills that consumption at the off-peak rate regardless of the hour, and bills everything else at a standard single rate.
Intelligent Octopus Go, OVO Charge Anytime and E.ON Next Drive use this hybrid model.
The session model is the structural shift since 2023. The supplier controls when the car charges (within a customer-set deadline), shifts charging into the cheapest half-hour blocks against the wholesale market, and passes the savings on as a flat session rate. The customer trades fine-grained control for a lower headline rate and zero load-shifting hassle.
Every UK EV tariff, ranked by off-peak window and structure
| Tariff | Off-peak window | Off-peak rate | Peak rate | Standing charge | Smart meter | EV proof | Exit fee |
|---|---|---|---|---|---|---|---|
| Octopus Intelligent Octopus Go | 6 hours 23:30 to 05:30 plus scheduled slots | Single off-peak rate; verify the live rate on the supplier page | Standard variable peak | Standard regional | SMETS2 required | Yes, chargepoint or car API | £0 |
| Octopus Go | 4 hours 00:30 to 04:30 | Off-peak fixed rate (verify live) | Higher peak rate fixed for term | Standard regional | SMETS2 required | No | £0 |
| Octopus Agile | Half-hourly wholesale-tracked | Variable, often negative overnight | Capped per Ofgem cap formula | Standard regional | SMETS2 required (HH export) | No | £0 |
| OVO Charge Anytime (add-on) | Any hour, session-metered | 7p per kWh (verify live) | OVO base tariff applies otherwise | OVO base tariff applies | SMETS2 required | Yes, compatible car or chargepoint | £0 add-on |
| E.ON Next Drive | 7 hours 00:00 to 07:00 | Fixed off-peak rate | Higher peak rate | Standard regional | SMETS2 required | Yes, V5C | £75 per fuel |
| EDF GoElectric 35h | 35 hours per week (5 hours nightly) | Fixed off-peak rate | Higher peak rate | Standard regional | SMETS2 required | Yes, V5C | £75 per fuel |
| EDF GoElectric 25h | 25 hours per week (split slots) | Lower off-peak rate | Lower peak rate than 35h | Standard regional | SMETS2 required | Yes, V5C | £75 per fuel |
| EDF GoElectric Overnight | 7 hours 00:00 to 07:00 | Fixed off-peak rate | Higher peak rate | Standard regional | SMETS2 required | Yes, V5C | £75 per fuel |
| British Gas Electric Driver | 5 hours 00:00 to 05:00 | Fixed off-peak rate | Higher peak rate | Standard regional | SMETS2 required | Yes, V5C | £50 per fuel |
| Scottish Power EV Saver | 4 hours 00:00 to 04:00 | Fixed off-peak rate | Higher peak rate | Standard regional | SMETS2 required | Yes, V5C | £75 per fuel |
Rates change quarterly. Verify the live off-peak rate on each supplier's page before switching; the structural detail above is stable for the 2026 product set.
Window length is not the only thing that matters
The published comparison sites lead with the lowest headline off-peak number. The number that actually decides the annual bill is the peak rate, because every household has hours of consumption outside the EV window (cooking, lighting, washing machine, electric shower) that price at peak.
Octopus Go runs a 4-hour off-peak window with a peak rate that has historically tracked roughly the standard variable. Octopus Intelligent Go runs a longer effective window through scheduled extra slots, with the same peak structure. The catch is that on a high-consumption household (4kW heat pump, electric oven, two EVs), the longer effective window matters more than 1p difference in headline off-peak rate. On a low-consumption household (one EV, gas heating, gas hob), the headline rate matters most because the peak hours are minimal. EDF GoElectric 25h vs 35h shows the same trade-off in pure time-of-use form. The 25h product has a lower peak rate than the 35h because EDF gives back less off-peak window. A driver on 8,000 miles a year and modest household usage often pays less on the 25h.
The session model: Intelligent Octopus Go, Charge Anytime, Next Drive
Intelligent Octopus Go reads the car's state of charge via the manufacturer's API (Tesla, Ford, Volkswagen Group, BMW, Stellantis) or via a compatible OZEV-approved chargepoint (Ohme, Wallbox Pulsar, Hypervolt). The customer sets a "ready by" time and a target percentage; Octopus schedules the charge across the cheapest half-hour blocks that night, exposes those blocks at the off-peak rate, and bills any unscheduled draw at the peak rate.
OVO Charge Anytime works as an add-on. The customer stays on the OVO base tariff for everything except EV charging, which OVO meters separately through the chargepoint or car API and bills at a flat 7p (verify live rate) regardless of time of day. The financial logic: OVO buys the wholesale electricity cheaply because they too schedule the charging session, and they pass on the discount only on the metered EV consumption.
E.ON Next Drive sits between the two models. There is a fixed nightly window (00:00 to 07:00) but the supplier also publishes a separate Drive Smart variant that uses car API scheduling. The Drive Smart variant has slightly lower headline rates and a marginally higher peak.
Why the session model is harder for new EV drivers to switch onto
Every session-model tariff requires either a compatible car make and model or a compatible chargepoint. The compatibility lists are short and updated unpredictably. A 2019 Nissan Leaf with no manufacturer API support cannot use Intelligent Octopus Go via the car route; the driver needs an Ohme or compatible chargepoint. Older cars and older chargepoints are routinely the rejection reason.
Smart meter requirements: SMETS2 is the gate
Every EV tariff in the table above requires a working SMETS2 smart meter sending half-hourly data to the Data Communications Company (DCC). SMETS1 meters in the original 2016 to 2018 wave are acceptable on some suppliers, but only after the DCC migration completed in their batch (BEIS data shows migration completion at over 99% of SMETS1 estate by end of 2025).
In practice, every new EV tariff customer in 2026 needs a SMETS2 install if they do not already have one. Lead time from booking to install runs 4 to 8 weeks depending on the supplier; suppliers will not switch the tariff to the EV variant until the meter is commissioned and sending data.
Here is where it breaks: some properties cannot get a SMETS2 install at all. Flats above shop level, basement meter cupboards with no signal, properties in known notspot postcodes (parts of rural Scotland, parts of west Wales, parts of the Pennines) have failed SMETS2 commissioning rates above the national average. Citizens Advice complaint figures for Q4 2025 show roughly 7% of smart-meter complaints related to failed commissioning, with rural and high-rise properties over-represented.
Devolved-nation pricing and standing-charge regional variation
EV tariff unit rates are nationally consistent within a supplier, but standing charges vary by Distribution Network Operator region. North Scotland (SSEN North) and Merseyside and North Wales (SP Energy Networks Manweb) have historically had the highest electricity standing charges, often 8p to 12p per day above the lowest-priced region (East Midlands, on the National Grid Electricity Distribution network).
For an EV driver doing 12,000 miles a year on a long-range model, the standing charge difference adds £30 to £45 per year. Smaller than the headline rate variation, but the standing charge applies on every day of the year regardless of whether the car charges.
Northern Ireland runs a separate market under the Utility Regulator. The available EV tariffs are different (Power NI's EV product is the main option) and the Ofgem cap does not apply. Cross-border comparisons against the GB tariffs above do not transfer.
Exit fees and the switch trap
The cheapest EV tariffs are fixed-rate products with an exit fee per fuel. Switching off a dual-fuel fixed EV tariff after 9 months can cost £100 to £150 in exit fees if both gas and electricity carry the fee. On the ground, this is the moment that pushes drivers to stay on a tariff that has become less competitive than the open market by month 12.
Octopus Go, Intelligent Octopus Go and Octopus Agile carry no exit fees. The trade-off is variable pricing: Octopus reserves the right to change the rate with 30 days' notice. Practical effect: more upside if the wholesale market falls, more exposure if it rises.
Frequently asked questions
Can a household run two cars on a single EV tariff?
Yes on every time-of-use tariff because the meter does not care which load draws the off-peak power. On session-model tariffs, both cars need to be on the compatibility list and both need to be scheduled through the supplier app.
Does the Ofgem default tariff cap apply to EV tariffs?
The cap formula applies to the standard variable component of a dual-rate EV tariff. Fixed EV tariffs are outside the cap because they are fixed-term contracts. Ofgem's Q2 2026 cap decision sets the underlying benchmark for what an EV tariff's peak rate can sustainably price against.
What happens if the chargepoint API or car API drops mid-charge?
On a session-model tariff, the supplier defaults the unscheduled draw to the peak rate. Most suppliers credit back the difference if the customer can show the outage was on the supplier's side. Octopus publishes session logs in the app for verification.
Can a tenant on a prepayment meter use an EV tariff?
No. Every EV tariff requires a credit-billed direct-debit account and a SMETS2 smart meter in credit mode. Prepayment customers can switch off prepayment first; Ofgem rules under SLC 27 require suppliers to offer that switch where it is safe to do so.
Are heat pump and EV tariffs the same product?
No, though Octopus Cosy and Intelligent Octopus Go can theoretically run on the same household. The session model bills only the EV consumption at the discounted rate, so a heat pump running mid-evening prices at peak unless the household is also on a dedicated heat pump tariff.
Do solar-export households get a worse deal on EV tariffs?
No. Export under the Smart Export Guarantee is metered separately on the SMETS2 import-export channel. The EV tariff prices the household's import only. Export rates are set by the SEG licensee and are unaffected.